1 files changed, 218 insertions, 0 deletions
diff --git a/backend/actualbudget_importer/src/transformers.rs b/backend/actualbudget_importer/src/transformers.rs
new file mode 100644
index 0000000..dd4d154
--- /dev/null
+++ b/backend/actualbudget_importer/src/transformers.rs
@@ -0,0 +1,218 @@
+use anyhow::Result;
+use budgeting_app_core::models::{
+    account::Account, budget_update::BudgetUpdate, category::Category, category_transfer::CategoryTransfer, date_utc::DateUtc, datetime_utc::DatetimeUtc, transaction::Transaction, transaction_categorisation::TransactionCategorisation
+};
+use core::panic;
+use std::hash::{DefaultHasher, Hash, Hasher};
+
+use crate::models::{actualbudget_account::ActualbudgetAccount, actualbudget_category::ActualbudgetCategory, actualbudget_date::ActualbudgetDate, actualbudget_transaction::ActualbudgetTransaction, actualbudget_zero_budget::ActualbudgetZeroBudget};
+
+pub fn transform_date(actualbudget_date: &ActualbudgetDate) -> Result<DatetimeUtc> {
+    actualbudget_date.to_iso().parse()
+}
+
+pub fn transform_accounts(
+    actualbudget_accounts: &[ActualbudgetAccount],
+    first_transaction_date: &DatetimeUtc,
+) -> Vec<Account> {
+    let mut accounts = Vec::<Account>::new();
+    for account in actualbudget_accounts {
+        accounts.push(transform_account(account, first_transaction_date));
+    }
+    accounts
+}
+
+fn transform_account(
+    actualbudget_account: &ActualbudgetAccount,
+    opening_date: &DatetimeUtc,
+) -> Account {
+    Account {
+        id: transform_id(&actualbudget_account.id.clone()),
+        name: actualbudget_account.name.clone(),
+        opening_balance: 0,
+        opening_date: opening_date.clone(),
+    }
+}
+
+pub fn transform_categories(
+    actualbudget_categories: &[ActualbudgetCategory],
+) -> Vec<Category> {
+    let mut categories = Vec::<Category>::new();
+    for actualbudget_category in actualbudget_categories {
+        categories.push(Category {
+            id: transform_id(&actualbudget_category.id.clone()),
+            name: actualbudget_category.name.clone(),
+        })
+    }
+    categories
+}
+
+fn transform_id(actualbudget_id: &str) -> i32 {
+    let mut hasher = DefaultHasher::new();
+    actualbudget_id.hash(&mut hasher);
+    (hasher.finish() % std::convert::TryInto::<u64>::try_into(i32::MAX).unwrap())
+        .try_into()
+        .unwrap()
+}
+
+pub fn transform_budget_updates(
+    actualbudget_zero_budgets: &[ActualbudgetZeroBudget],
+) -> Result<Vec<BudgetUpdate>> {
+    let mut budget_updates = Vec::<BudgetUpdate>::new();
+    for zero_budget in actualbudget_zero_budgets {
+        let first_zero_budget_in_category = get_first_zero_budget_in_category(
+            actualbudget_zero_budgets,
+            &zero_budget.category_id.clone(),
+        );
+        if first_zero_budget_in_category.is_some_and(|zb| zb.id == zero_budget.id) {
+            continue;
+        }
+        budget_updates.push(BudgetUpdate {
+            id: transform_id(&zero_budget.id.clone()),
+            category_id: transform_id(&zero_budget.category_id.clone()),
+            date: DateUtc::from(transform_date(&zero_budget.month.clone())?),
+            new_budget: zero_budget.amount.try_into().unwrap(),
+            new_period: 30,
+        })
+    }
+    Ok(budget_updates)
+}
+
+fn get_first_zero_budget_in_category(
+    actualbudget_zero_budgets: &[ActualbudgetZeroBudget],
+    actualbudget_category_id: &str,
+) -> Option<ActualbudgetZeroBudget> {
+    let mut category_zero_budgets = actualbudget_zero_budgets.to_vec();
+    category_zero_budgets.retain(|zb| zb.category_id == actualbudget_category_id);
+    category_zero_budgets
+        .iter()
+        .min_by_key(|zb| zb.month.clone())
+        .cloned()
+}
+
+pub fn transform_transactions(
+    actualbudget_transactions: &[ActualbudgetTransaction],
+    actualbudget_category_transfers_account: &ActualbudgetAccount,
+) -> Result<(Vec<Transaction>, Vec<TransactionCategorisation>)> {
+    let mut transactions = Vec::<Transaction>::new();
+    let mut transaction_categorisations = Vec::<TransactionCategorisation>::new();
+
+    let mut actualbudget_transactions = actualbudget_transactions.to_vec();
+    actualbudget_transactions
+        .retain(|t| t.category_id.clone() != actualbudget_category_transfers_account.id.clone());
+    let mut parent_actualbudget_transactions = actualbudget_transactions.to_vec();
+    parent_actualbudget_transactions.retain(|t| t.is_parent);
+    let mut child_actualbudget_transactions = actualbudget_transactions.to_vec();
+    child_actualbudget_transactions.retain(|t| t.is_child);
+    let mut atomic_actualbudget_transactions = actualbudget_transactions.to_vec();
+    atomic_actualbudget_transactions.retain(|t| !t.is_parent && !t.is_child);
+
+    for atomic_actualbudget_transaction in atomic_actualbudget_transactions {
+        let transaction_id = transform_id(&atomic_actualbudget_transaction.id);
+
+        transactions.push(Transaction {
+            id: transaction_id,
+            description: atomic_actualbudget_transaction.notes,
+            payee: atomic_actualbudget_transaction.payee,
+            quantity: atomic_actualbudget_transaction.amount.try_into().unwrap(),
+            date: transform_date(&atomic_actualbudget_transaction.date)?,
+            account_id: transform_id(&atomic_actualbudget_transaction.account_id),
+        });
+
+        transaction_categorisations.push(TransactionCategorisation {
+            id: transaction_id,
+            description: String::new(),
+            quantity: atomic_actualbudget_transaction.amount.try_into().unwrap(),
+            transaction_id,
+            category_id: transform_id(&atomic_actualbudget_transaction.category_id),
+        });
+    }
+
+    for parent_actualbudget_transaction in parent_actualbudget_transactions {
+        let mut child_actualbudget_transactions = child_actualbudget_transactions.to_vec();
+        child_actualbudget_transactions.retain(|t| {
+            t.parent_id
+                .clone()
+                .is_some_and(|parent_id| parent_id == parent_actualbudget_transaction.id.clone())
+        });
+
+        let transaction_id = transform_id(&parent_actualbudget_transaction.id);
+
+        transactions.push(Transaction {
+            id: transaction_id,
+            description: parent_actualbudget_transaction.notes,
+            payee: parent_actualbudget_transaction.payee,
+            quantity: parent_actualbudget_transaction.amount.try_into().unwrap(),
+            date: transform_date(&parent_actualbudget_transaction.date)?,
+            account_id: transform_id(&parent_actualbudget_transaction.account_id),
+        });
+
+        for child_actualbudget_transaction in child_actualbudget_transactions {
+            transaction_categorisations.push(TransactionCategorisation {
+                id: transform_id(&child_actualbudget_transaction.id),
+                description: child_actualbudget_transaction.notes,
+                quantity: child_actualbudget_transaction.amount.try_into().unwrap(),
+                transaction_id,
+                category_id: transform_id(&child_actualbudget_transaction.category_id),
+            });
+        }
+    }
+
+    Ok((transactions, transaction_categorisations))
+}
+
+pub fn transform_category_transfers(
+    actualbudget_transactions: &[ActualbudgetTransaction],
+    actualbudget_category_transfers_account: &ActualbudgetAccount,
+) -> Vec<CategoryTransfer> {
+    let mut category_transfers = Vec::<CategoryTransfer>::new();
+
+    let mut actualbudget_category_transfers = actualbudget_transactions.to_vec();
+    actualbudget_category_transfers
+        .retain(|t| t.category_id.clone() == actualbudget_category_transfers_account.id.clone());
+    let mut actualbudget_parent_category_transfers = actualbudget_category_transfers.to_vec();
+    actualbudget_parent_category_transfers.retain(|t| t.is_parent);
+    let mut actualbudget_child_category_transfers = actualbudget_category_transfers.to_vec();
+    actualbudget_child_category_transfers.retain(|t| t.is_child);
+
+    for actualbudget_parent_category_transfer in actualbudget_parent_category_transfers {
+        let mut actualbudget_child_category_transfers =
+            actualbudget_child_category_transfers.to_vec();
+        actualbudget_child_category_transfers.retain(|t| {
+            t.parent_id
+                .clone()
+                .is_some_and(|parent_id| parent_id == actualbudget_parent_category_transfer.id)
+        });
+
+        if actualbudget_child_category_transfers.len() != 2 {
+            panic!("Category transfers should always have exactly two children.");
+        }
+
+        let category_1 = actualbudget_child_category_transfers[0].clone();
+        let category_2 = actualbudget_child_category_transfers[1].clone();
+
+        // To avoid duplicates
+        if category_1.amount >= 0 {
+            continue;
+        }
+
+        if actualbudget_child_category_transfers[0].amount
+            != -actualbudget_child_category_transfers[1].amount
+        {
+            panic!("Category transfer children should sum to zero.");
+        }
+
+        category_transfers.push(CategoryTransfer {
+            id: transform_id(&actualbudget_parent_category_transfer.id),
+            description: actualbudget_parent_category_transfer.notes,
+            quantity: actualbudget_child_category_transfers[0]
+                .amount
+                .try_into()
+                .unwrap(),
+            from_category_id: transform_id(&category_1.id),
+            to_category_id: transform_id(&category_2.id),
+        });
+    }
+
+    category_transfers
+}